I have an episode-id and from this I want to derive the series.
How can I do that?
This is what I tried:
ia = IMDb()
movie = ia.get_movie(id)
if movie['kind'] == "episode":
series = movie['episode of']
print(series)
This gives me only the series title, allthough the documentation says, 'episode of' gives in addition the id of the series.
The series object stored in the 'episode of' key is an instance of the Movie class, so you can access the series ID using:
imdbID = series.movieID
You can also update the information of the Movie instance so that more information (besides title and ID) are collected, with something like:
ia.update(series)
Related
I have 2 tables contractPoint and contractPointHistory
ContractPointHistory
ContractPoint
I would like to get contractPoint where point will be subtracted by pointChange. For example: ContractPoint -> id: 3, point: 5
ContractPointHistory has contractPointId: 3 and pointChange: -5. So after manipulating point in contractPoint should be 0
I wrote this code, but it works just for getRawMany(), not for getMany()
const contractPoints = await getRepository(ContractPoint).createQueryBuilder('contractPoint')
.addSelect('"contractPoint".point + COALESCE((SELECT SUM(cpHistory.point_change) FROM contract_point_history AS cpHistory WHERE cpHistory.contract_point_id = contractPoint.id), 0) AS points')
.andWhere('EXTRACT(YEAR FROM contractPoint.validFrom) = :year', { year })
.andWhere('contractPoint.contractId = :contractId', { contractId })
.orderBy('contractPoint.grantedAt', OrderByDirection.Desc)
.getMany();
The method getMany can be used to select all attributes of an entity. However, if one wants to select some specific attributes of an entity then one needs to use getRawMany.
As per the documentation -
There are two types of results you can get using select query builder:
entities or raw results. Most of the time, you need to select real
entities from your database, for example, users. For this purpose, you
use getOne and getMany. But sometimes you need to select some specific
data, let's say the sum of all user photos. This data is not an
entity, it's called raw data. To get raw data, you use getRawOne and
getRawMany
From this, we can conclude that the query which you want to generate can not be made using getMany method.
Let's say I have this file:
movie_id,title,genres
95004,Superman/Doomsday (2007),Action|Animation
136297,Mortal Kombat: The Journey Begins (1995),Action
193565,Gintama: The Movie (2010),Action|Animation|Comedy|Sci-Fi
193573,Love Live! The School Idol Movie (2015),Animation
I load it like this:
movies = LOAD 'movies.csv' USING PigStorage(',') AS (moviesId:int, title:chararray, genres: chararray);
movies = FOREACH movies GENERATE movieId, title, STRSPLIT(genres,'\\|') as genres;
describe a; //a: {movieId: int,title: chararray,genres: ()}
Example of dump a results:
...
(193581,Black Butler: Book of the Atlantic (2017),(Action,Animation,Comedy,Fantasy))
(193583,No Game No Life: Zero (2017),(Animation,Comedy,Fantasy))
...
Now, if I undestand correctly, the field genres is of type tuple. The question is how can I do a query such as: "get all the action movies?". I don't know how to check if a specific element is present in the tuple genres.
I know how to do this with a Python UDF function, but I would like to know if it is possible without one. Maybe I should load the file differently.
Thank you for your help.
If you are happy to put the genres into a bag rather than into a tuple (I think this would be more appropriate since the number of genres varies from record to record). This could be then solved with a nested FOREACH by filtering the bag for specific genres then testing to see if the bag is not empty.
movies = LOAD 'movies.csv' USING PigStorage(',') AS (moviesId:int, title:chararray, genres: chararray);
moviesSplit = FOREACH movies GENERATE movieId, title, TOKENIZE(genres,'|') as genres;
actionTest = FOREACH moviesSplit {
action = FILTER genres by $0 == 'Action';
GENERATE *, action;
actionMovies = FILTER actionTest BY NOT IsEmpty(action);
I have two models a parent and the son contains two float fields
one of the values this calculates according to the other but when I change the father how can be my calculating function.
Here is my example:
class A(models.model):
trv_ids = fields.One2many(classB,id_A)
class B(models.model):
id_A = fields.Many2one(classA)
qtite = fields.float(default=0)
qtite1 = fields.float(default=0,compute=?????)
qtite1 gets the value of qtite when I change parent
as the example of cumulated amount becomes previous quantity the next month.
Thanks
If i understood right i think what you need is something like this:
#api.depends('id_A')
def _compute_qtie1(self):
for record in self:
record.qtite1 = record.qtite
qtite1 = fields.float(compute=_compute_qtie1, store=True)
The depends is what triggers (any time you change the id_A field in the record) the compute method, if you dont store it in the DB it will re-calculate every time you open a view that contains the record.
I have 4 model like this
class Site(models.Model):
name = models.CharField(max_length=200)
def get_lowest_price(self, mm_date):
'''This method returns lowest product price on a site at a particular date'''
class Category(models.Model):
name = models.CharField(max_length=200)
site = models.ForeignKey(Site)
class Product(models.Model):
name = models.CharField(max_length=200)
category = models.ForeignKey(Category)
class Price(models.Model):
date = models.DateField()
price = models.IntegerField()
product = models.ForeignKey(Product)
Here every have many category, every category have many product. Now product price can change every day so price model will hold the product price and date.
My problem is I want list of site filter by price range. This price range will depends on the get_lowest_price method and can be sort Min to Max and Max to Min. Already I've used lambda expression to do that but I think it's not appropriate
sorted(Site.objects.all(), key=lambda x: x.get_lowest_price(the_date))
Also I can get all site within a price range by running a loop but this is also not a good idea. Please help my someone to do the query in right manner.
If you still need more clear view of the question please see the first comment from "Ishtiaque Khan", his assumption is 100% right.
*In these models writing frequency is low and reading frequency is high.
1. Using query
If you just wanna query using a specific date. Here is how:
q = Site.objects.filter(category__product__price__date=mm_date) \
.annotate(min_price=Min('category__product__price__price')) \
.filter(min_price__gte=min_price, min_price__lte=max_price)
It will return a list of Site with lowest price on mm_date fall within range of min_price - max_price. You can also query for multiple date using query like so:
q = Site.objects.values('name', 'category__product__price__date') \
.annotate(min_price=Min('category__product__price__price')) \
.filter(min_price__gte=min_price, min_price__lte=max_price)
2. Eager/pre-calculation, you can use post_save signal. Since the write frequency is low this will not be expensive
Create another Table to hold lowest prices per date. Like this:
class LowestPrice(models.Model):
date = models.DateField()
site = models.ForeignKey(Site)
lowest_price = models.IntegerField(default=0)
Use post_save signal to calculate and update this every time there. Sample code (not tested)
from django.db.models.signals import post_save
from django.dispatch import receiver
#receiver(post_save, sender=Price)
def update_price(sender, instance, **kwargs):
cur_price = LowestPrice.objects.filter(site=instance.product.category.site, date=instance.date).first()
if not cur_price:
new_price = LowestPrice()
new_price.site = instance.product.category.site
new_price.date = instance.date
else:
new_price = cur_price
# update price only if needed
if instance.price<new_price.lowest_price:
new_price.lowest_price = instance.price
new_price.save()
Then just query directly from this table when needed:
LowestPrice.objects.filter(date=mm_date, lowest_price__gte=min_price, lowest_price__lte=max_price)
Solution:
from django.db.models import Min
Site.objects.annotate(
price_min=Min('categories__products__prices__price')
).filter(
categories__products__prices__date=the_date,
).distinct().order_by('price_min') # prefix '-' for descending order
For this to work, you need to modify the models by adding a related_name attribute to the ForeignKey fields.
Like this -
class Category(models.Model):
# rest of the fields
site = models.ForeignKey(Site, related_name='categories')
Similary, for Product and Price models, add related_name as products and prices in the ForeignKey fields.
Explanation:
Starting with related_name, it describes the reverse relation from one model to another.
After the reverse relationship is setup, you can use them to inner join the tables.
You can use the reverse relationships to get the price of a product of a category on a site and annotate the min price, filtered by the_date. I have used the annotated value to order by min price of the product, in ascending order. You can use '-' as a prefix character to do in descending order.
Do it with django queryset operations
Price.objects.all().order_by('price') #add [0] for only the first object
or
Price.objects.all().order_by('-price') #add [0] for only the first object
or
Price.objects.filter(date= ... ).order_by('price') #add [0] for only the first object
or
Price.objects.filter(date= ... ).order_by('-price') #add [0] for only the first object
or
Price.objects.filter(date= ... , price__gte=lower_limit, price__lte=upper_limit ).order_by('price') #add [0] for only the first object
or
Price.objects.filter(date= ... , price__gte=lower_limit, price__lte=upper_limit ).order_by('-price') #add [0] for only the first object
I think this ORM query could do the job ...
from django.db.models import Min
sites = Site.objects.annotate(price_min= Min('category__product__price'))
.filter(category__product__price=mm_date).unique().order_by('price_min')
or /and for reversing the order :
sites = Site.objects.annotate(price_min= Min('category__product__price'))
.filter(category__product__price=mm_date).unique().order_by('-price_min')
I'm new to web development and rails, and I'm trying to construct a query object for my first time. I have a table Players, and a table DefensiveStats, which has a foriegn-key player_id, so each row in this table belongs to a player. Players have a field api_player_number, which is an id used by a 3rd party that I'm referencing. A DefensiveStats object has two fields that are relevant for this query - a season_number integer and a week_number integer. What I'd like to do is build a single query that takes 3 parameters: an api_player_number, season_number, and week_number, and it should return the DefensiveStats object with the corresponding season and week numbers, that belongs to the player with api_player_number = passed in api_player_number.
Here is what I have attempted:
class DefensiveStatsWeekInSeasonQuery
def initialize(season_number, week_number, api_player_number)
#season_number = season_number
#week_number = week_number
#api_player_number = api_player_number
end
# data method always returns an object or list of object, not a relation
def data
defensive_stats = Player.where(api_player_number: #api_player_number)
.joins(:defensive_stats)
.where(season_number:#season_number, week_number: #week_number)
if defensive_stats.nil?
defensive_stats = DefensiveStats.new
end
defensive_stats
end
end
However, this does not work, as it performs the second where clause on the Player class, and not the DefensiveStats class -> specifically, "SQLite3::SQLException: no such column: players.season_number"
How can I construct this query? Thank you!!!
Player.joins(:defensive_stats).where(players: {api_player_number: #api_player_number}, defensive_stats: {season_number: #season_number, week_number: #week_number})
OR
Player.joins(:defensive_stats).where("players.api_player_number = ? and defensive_stats.season_number = ? and defensive_stats.week_number = ?", #api_player_number, #season_number, #week_number)